Battery/Alternator??

[NewC5dude]

Hi guys, loving the new C5, got use to it now. No problems apart from ASR/ESP fault, and also now have a issue with battery or Alternator. Symptoms are, battery light on and speedo dial was going up and down. Gave connections a clean and they look all good. Reconnected them and had no issues for a few hours. Lights go dim and radio cuts out for half a second. My thought here is a new battery needed hopefully not a new alternator seen them at £330 . Cheers.

[GiveMeABreak]

A weak or poor battery will cause havoc with electrical systems - get it changed as soon as possible or you will end up with more grief.

Make sure you follow the guide for both removing and replacing the battery:

BSI Reset / Battery Disconnect / Reconnect Procedure

[NewC5dude]

Yeah hoping to get it changed wednesday. Battery light is still on when ignition is on so thats what makes me think defo battery

[Hell Razor5543]

I would get the battery checked first.

How many miles has the car done? It is possible that (with high mileage) the brushes on the alternator have worn out. However, I don't know if it is possible to change them (I was able to do so on my BX some 15 years ago when they failed). If the brushes are on the way out the alternator cannot provide a decent charge for the battery.

[GiveMeABreak]

Yeah hoping to get it changed wednesday. Battery light is still on when ignition is on so thats what makes me think defo battery

Another indication of the battery is when the display needles start going up and down on the dash erratically as they are all electronic.

[wheeler]

You need to confirm the alternator is charging the battery first. ABS lights on & lights dimming are also classic signs of a failing alternator or even a poor earth. They can start to fail intermittently. It can stop charging then go over a bump & it starts charging again. Of course this & everything said above is pure guesswork till you get a meter on it & do some further checks.

[NewC5dude]

I would get the battery checked first.

How many miles has the car done? It is possible that (with high mileage) the brushes on the alternator have worn out. However, I don't know if it is possible to change them (I was able to do so on my BX some 15 years ago when they failed). If the brushes are on the way out the alternator cannot provide a decent charge for the battery.

113k miles. The alternator looks pretty worn. Had no problems at all today with it, so my guess is the battery.

[NewC5dude]

You need to confirm the alternator is charging the battery first. ABS lights on & lights dimming are also classic signs of a failing alternator or even a poor earth. They can start to fail intermittently. It can stop charging then go over a bump & it starts charging again. Of course this & everything said above is pure guesswork till you get a meter on it & do some further checks.

Alternator is charging battery, so am thinking the battery is not holding a charge . Trying to get it booked in asap but my local garages sucks, well over priced and do not do a very good job at anything. So looking out and about.

[NewC5dude]

Yeah hoping to get it changed wednesday. Battery light is still on when ignition is on so thats what makes me think defo battery

Another indication of the battery is when the display needles start going up and down on the dash erratically as they are all electronic.

That's exactly what happened, my speed needle and rev needle was up and down up and down for maybe 2secs the all returned to normal. My car would not lock with buttons on the keys thats what made me go out and check.

[GiveMeABreak]

I've seen this happen lots of times - but as said - if you can confirm that the alternator is charging (just put a multi meter on the terminals and see if you are getting anything around 14.3- 14.7V), then it's you battery.

[myglaren]

My 2003 C5 had a habit of randomly going nuts - although it showed ∓14.7V the CD player would go nuts for a few seconds then shut down.
All the gauges would zero the occasionally flick to max then drop to zero again, meanwhile the panel lights would flash, the aircon would shut down, wipers and indicators stop working and the central display blank out.

This would usually last a couple of minutes then all would reset to normal as though nothing had happened. Sometimes I would have to stop at a safe place for a few minutes, turn the car off and wait five minutes before restarting.

One of the last times was at the Northern rally, on the way up the A1 it went haywire. I just carried on, staying in lane one behind someone doing approx 60mph and waited for it to come back, took twenty minutes on that occasion.

About a year ago the alternator stopped charging. Took it to my usual garage who confirmed it dead, replaced for £160 (LUK) which was less than I had estimated for the cost of just an alternator, around £200.
All well since then.

[Stickyfinger]

I had my Alternator repaired locally to me, new brushes/Slip-ring/Frn't bearing....all in £45. Saved me £120

[NewC5dude]

Hi guys it was my alternator that was needing replace . Thanks for the help.